The present invention relates to a liquid fuel burner of the type utilizing a liquid fuel atomizer comprising a hollow horn which is oscillated at an ultrasonic frequency and includes a nozzle.
In the liquid fuel burner of the type described above, the liquid fuel atomizing surface at one end of the hollow horn is oscillated at an ultrasonic frequency, and liquid fuel forms a very thin film over the atomizing surface under the influence of surface tension of fuel oil. The thin fuel film is broken into finely divided particles as the atomizing surface oscillates at an ultrasonic frequency. In the liquid fuel atomizing method utilizing the ultrasonic wave energy, the degree of atomization is greatly dependent upon the diameter of the nozzle, the quality of the thin oil film and the area of the atomizing surface. When the above three conditions are not satisfied, the power input to the atomizer must be increased regardless of the flow rate of fuel oil. When the finely divided particles are large in size and if the atomization is not uniform, not only is the combustion efficiency lowered but also the breakdown of the atomizer occurs due to the thermal stress, thus resulting in a short service life.